My test OpenBSD: load from livecd bsdanywhere46-amd64
in different consoles: dd if=/dev/wd0c of=/dev/null bs=1m dd if=/dev/wd0c of=/dev/null bs=1m dd if=/dev/wd0c of=/dev/null bs=1m iostat top run: dd if=/dev/urandom of=/dev/null and disk read speed jump from 22Mb/s to 0.9Mb/s! renice 20 for last dd - throughput not change! renice -20 for first three dd - throughput not change! For check renice, run renice -20 for last dd - OpenBSD froze, even mouse. It is not secure. One script or program may load CPU and database or another servers lost speed in disk operations. In Linux (test on 2.6.35 libre) renice work correct... Why renice not work in OpenBSD? -- Dmitry Telegin
